A paleomagnetist on board the JOIDES Resolution ocean drilling vessel

I was having a shower at the beginning of our last day on the ship- warm and comfort shower- and suddenly I smell something different, something like mold. I come out to the deck to realise that we have docked in Reykjavik, that it was the smell of land, the smell of the end of our two months expedition spent in the middle of the North Atlantic Ocean. A turmoil of feelings where silence would prevail. The entire scientist staff, the technical staff, some of the crew, the Capitan, we were all standing still, under a Nordic cold sun, watching the docking operations. The ever-changing colour of the Ocean turned to dark green port-like waters, full of birds, docks and ducks, land all around! It has been two months without seeing (and smelling) land.

We were coming back from our two months sailing in the legendary ship, the JOIDES Resolution (JR), for the International Ocean Discovery Program (IODP), Expedition 395 “Reykjanes Mantle Convection and Climate: Mantle Dynamics, Paleoceanography and Climate Evolution in the North Atlantic Ocean” with Ross Parnell-Turner from Scripps, California, Anne Briais from Toulouse in France as Chiefs, and Leah LeVay from IODP Texas A&M University as Project Manager/ Staff Scientists. We should have sailed in 2020 but because of the global Covid-19 pandemic, the JR Expedition sailed with only a few technical staff and became Expedition 384; one year later the expedition was postponed, becoming Expedition 395C, with only Leah as a Science Staff. Finally, this year, the entire Science Staff could sail. After a good amount of last-minute shopping, including chocolate, tea, biscuits and a hard disk, we set sail from the Ponta Delgata port in Sao Miguel (Azores, Portugal) on the 12th of June to drill a transect of 4 out of the 6 sites originally planned (2 were completed during Expedition 395C) from the East to West in the North Atlantic Ocean, south of Iceland. 

My job as a shipboard paleomagnetist was to measure all the sediment and hard rock cores in the Superconducting Rock Magnetometer to reconstruct the Earth's magnetic field changes in polarity to provide an age of the sediments. We compare these polarity changes recorded in the oceanic sediments (normal polarity is like the present day setting while the reverse polarity is when the North pole flips to the South Pole) with a global reference scale (called Geomagnetic Polarity Time Scale; Ogg 2020) to estimate the age of the sediments, and then we combine the paleomagnetic observations with the encounters of microfossils which also provide an independent age. We had 12 hours shifts and at the end of each shift (at noon and at midnight), we had a crossover meeting with all the other groups of scientists- the sedimentologists, the physical properties scientists, the geochemists, the stratigraphic correlators, the palaeontologists, us the paleomagnetists, the outreach officer, the staff scientists and the two chiefs. 

My typical day started with a one hour gym session in the morning, breakfast/lunch (which was always delicious), crossover meeting with my counterpart in the same role, Sarah, and then here we go, measuring all day meters and meters of ‘boring’ muds. I say ‘boring’ as their properties, colour, granulometry did not change much, but what I really mean was ‘amazing’ and ‘ideal’ for paleomagnetic studies as they require homogenous lithology and continuous sedimentation to capture with a clean signal all the polarity changes! Do not think that Sarah and I did all by ourselves... An amazing team of technicians was always there, ready to help answer questions and fix some mistakes (yes, we make mistakes and it’s ok). For every week there was a weekly report, for every completed site there was a site report and site summary and a meeting with everyone else to share the fresh off the measurements and interpretation results. Yes, hard work! In a hectic around the clock pace of laboratory work, data interpretation and report-writing, science was unveiling under our amazed eyes. Fuelled by coffee, music and peer comfort with frequent and short breaks (and a longer one for lunch/dinner), we made it! We drilled all the sites, exceeding the expectations, drilling more than 4 km of sediment cores, and 120m of basalts, nearly breaking the record of the deepest site ever drilled in one expedition. The Ocean was clement, calm for most of the time, blue, grey, silver, black, flock of birds were around us and some cetaceous visited us. It was simply an amazing experience, for the amazing group of scientists bringing their different expertise to the table, to achieve the expedition's goals and advance science…but I am sad that this program will end in just nine months.

That’s it. The JR needed repairs, but the main funding body cut the expenses out and none of the other international contributors stepped up to challenge. Nobody else will be able to sail on the legendary JR, breaking the boundaries of science by deep ocean drilling. We take comfort that the legacy remains for future scientists, of many kilometers of rock in the Core repositories of College Station in Texas and in Bremen but the specialised expertise to conduct a state of art floating laboratory are sadly lost, forever.





by Dr. Anita Di Chiara (she/her)

Researcher

INGV - Rome

One of the crew on the JR Expedition 395

 

 

 

Photo Credits-
 
1 and 2: Jen Field, Outreach Officer
3: Dr. Sevi Modestou, shipboard sedimentologist

0 comments:

Post a Comment